1. Use primarily compound exercises rather than isolation exercises. Compound exercises are multi-joint movements that work more than one muscle at a time. Stop wasting time on Leg Extensions, Bicep Curls and Tricep Kickbacks. Concentrate on Lunges, Squats, Presses, Pushups, Deadlifts, Rows, etc. You'll not only save time but compound exercises are more functional (similar to how our body works in real life) and burn more calories.
2. Instead of doing 2 or 3 sets of the same exercise and resting between each set, pair a lower body and upper body exercise in a superset. For example, do a set of Squats followed immediately by a Row. Then, rest as needed and repeat.
3. Get off the machines. Most people are familiar with the strength training circuits used in many gyms. You'll get a better workout by using free weights (dumbbells, barbells, medicine balls, kettlebells, etc.). Why?
a. Many of those machines isolate muscles. See #1.
b. You don't get the full benefit of an exercise when seated on a machine. Your body doesn't need to work as hard because the machine guides the movement and supports your body weight. With free weights you need to lift and guide the weight, and also stabilize yourself so more muscles are involved.
(Please note, the above comments do not apply to the cable machine but that's an entire article of its own.)
4. Use challenging weights. Forget the "high reps, low weigh to tone" B.S. To get the look that people refer to as "toned", you need to reduce the amount of fat covering the muscles. To do that, you need to challenge yourself in your workouts. You'll save time and get far better results by doing sets of 6-12 reps (and sometimes 15) than by doing sets of 20-25 reps or more.
5. Ditch the slow, steady cardio workouts and replace them with metabolic circuits or cardio intervals.